During the first half of 1925 works began on the overground section of Ferrocarril Metropolitano de Barcelona. It is in this section, adjoining the entrance to the tunnel that takes the line to plaça de Catalunya, that Mercat Nou station was built.

Mercat Nou station opened on 10 June 1926 and had two platforms, each 50 metres long covered by a metal canopy, and with two entrances, one per each platform, from carrer de la Riera del Tena. In 1957, both platforms were extended to 70 metres and a third entrance was opened from carrer dels Jocs Florals.

The station maintained this layout until 2008 when, due to the covering of the Sants railway corridor, underwent a complete renovation. Both platforms were replaced by one central platform, the station was covered by a concrete estructure, and only one entrance remained, a large concourse area wich was built under the tracks wich is accessed from carrer de la Riera del Tena.